The present invention relates to an arrangement in a press with an eccentric shaft for the adjustment of the ram stroke by adjusting the resulting eccentricity of an eccentric and of an eccentric bushing supported thereon, on which is supported a connecting rod, whereby the eccentric bushing is selectively released and fixed in the direction of rotation on the eccentric by actuating means, and whereby the released eccentric bushing is fixed at a part non-rotating with the eccentric shaft and the eccentric shaft is rotated in this fixed condition for the purpose of adjusting the ram stroke.
Such arrangements are known, for example, from the DE-A 25 34 626, from the DE-A 27 40 382, from the DE-A 34 21 184 and from the DE-U 81 27 545, and more particularly for presses with only a single connecting rod (single-point presses) as as well as for those with several connecting rods (multi-point presses). Common to all of these prior art arrangements is the fact that for disengaging and fixing the eccentric bushing on the eccentric, they use a fixed and locked operating actuating means such as internal teeth, external teeth and end teeth and claw rings. These types of actuating means have disadvantages in that they can be brought into engagement only in steps by reason of the fixed and locking inter-engagement. Thus the engagement cannot be completely free of play and the danger of subsequent misalignment exists during operation of the machine and in case of frequent actuation of the adjustment.